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Many naturally occurring and human-induced activities result in the emission of nitrogen- and sulfur-containing compounds into the atmosphere. Precipitation is an important process by which compounds are scavenged from the atmosphere and deposited onto the earth's surface. The purpose of this paper is to compare the emissions of nitrogen oxides (NOx) and sulfur dioxide (SO2) in each of the 48 contiguous states in the USa with measured wet deposition of nitrate (NO3-) and sulfate (SO42-) in each state for the year 1990. With one exception (Vermont),wet deposition of N as nitrate was less than emissions of N as nitrogen oxides on a statewide basis in 1990. The median wet N deposition/emission value was 0.21. Wet plus dry N deposition of nitrate was estimated to represent 43% of NOx emissions in North Carolina. Wet deposition of S was less than emissions in 1990 in all but fivestates (Vermont, Maine, Arkansas, Nebraska, and South Dakota). The median value of wet deposition of sulfate/SO2 emissions was0.34. In North Carolina, dry deposition of sulfate was estimated to represent an additional 21% of emissions, so that total deposition accounted for 60% of S emissions. Net transport of N and S is likely animportant part of the discrepancy between emissions and deposition. [ABSTRACT FROM AUTHOR]

A primary sink of air pollutants and their precursors is dry deposition. Dry deposition estimates differ across chemical transport models, yet an understanding of the model spread is incomplete. Here, we introduce Activity 2 of the Air Quality Model Evaluation International Initiative Phase 4 (AQMEII4). We examine 18 dry deposition schemes from regional and global chemical transport models as well as standalone models used for impact assessments or process understanding. We configure the schemes as single-point models at eight Northern Hemisphere locations with observed ozone fluxes. Single-point models are driven by a common set of site-specific meteorological and environmental conditions. Five of eight sites have at least 3 years and up to 12 years of ozone fluxes. The interquartile range across models in multiyear mean ozone deposition velocities ranges from a factor of 1.2 to 1.9 annually across sites and tends to be highest during winter compared with summer. No model is within 50 % of observed multiyear averages across all sites and seasons, but some models perform well for some sites and seasons. For the first time, we demonstrate how contributions from depositional pathways vary across models. Models can disagree with respect to relative contributions from the pathways, even when they predict similar deposition velocities, or agree with respect to the relative contributions but predict different deposition velocities. Both stomatal and nonstomatal uptake contribute to the large model spread across sites. Our findings are the beginning of results from AQMEII4 Activity 2, which brings scientists who model air quality and dry deposition together with scientists who measure ozone fluxes to evaluate and improve dry deposition schemes in the chemical transport models used for research, planning, and regulatory purposes., Competing Interests: Author contributions. OEC led the manuscript’s direction and writing, data processing and analysis, and coordination among authors. DS and CH contributed to the manuscript’s direction, data processing, and coordination among authors. JOB contributed CMAQ STAGE results and documentation. SB contributed DO3SE results and documentation. PC contributed GEM-MACH results and documentation. MC contributed data from Easter Bush and Auchencorth Moss. LE contributed DO3SE results and documentation and assisted with direction. JF contributed IFS results and documentation and assisted with direction. EF, QL, and ET contributed data from Ramat Hanadiv. SG assisted with direction. LG contributed MLC-CHEM results and documentation. OG, IG, and GM contributed data from Ispra. CDH assisted with direction and contributed GEOS-Chem results and documentation. LH and TW contributed data from Bugacpuszta. VH contributed model results and documentation from IFS. PAM contributed model results and documentation from GEM-MACH and assisted with direction. IM and TV contributed data from Hyytiälä. JWM contributed data from Harvard Forest. JLPC and RSJ contributed WRF-Chem results and documentation. JP and LR contributed M3Dry results and documentation. RS, ZW, and LZ contributed data from Borden Forest. SJS assisted with data processing and assisted with direction. SS and APKT contributed TEMIR results and documentation. All authors contributed to manuscript writing and useful discussions on data analysis and processing and results. Competing interests. At least one of the (co-)authors is a member of the editorial board of Atmospheric Chemistry and Physics. The peer-review process was guided by an independent editor, and the authors also have no other competing interests to declare.

Opportunistic screening for osteoporosis can be performed using low-dose computed tomography (LDCT) imaging obtained for other clinical indications. In this study we explored the CT-derived bone mineral density (BMD) and prevalence of osteoporosis from thoracic LDCT in a large population cohort of Chinese men and women. A total of 69,095 adults (40,733 men and 28,362 women) received a thoracic LDCT scan for the purpose of lung cancer screening between 2018 and 2019, and data were obtained for analysis from the China Biobank Project, a prospective nationwide multicenter population study. Lumbar spine (L 1 -L 2 ) trabecular volumetric bone mineral density (vBMD) was derived from these scans using quantitative computed tomography (QCT) software and the American College of Radiology QCT diagnostic criteria for osteoporosis were applied. Geographic regional differences in the prevalence of osteoporosis were assessed and the age-standardized, population prevalence of osteoporosis in Chinese men and women was estimated from the 2010 China census. The prevalence of osteoporosis by QCT for the Chinese population aged >50 years was 29.0% for women and 13.5% for men, equating to 49.0 million and 22.8 million, respectively. In women, this rate is comparable to estimates from dual-energy X-ray absorptiometry (DXA), but in men, the prevalence is double. Prevalence varied geographically across China, with higher rates in the southwest and lower rates in the northeast. Trabecular vBMD decreased with age in both men and women. Women had higher peak trabecular vBMD (185.4 mg/cm 3 ) than men (176.6 mg/cm 3 ) at age 30 to 34 years, but older women had lower trabecular vBMD (62.4 mg/cm 3 ) than men (92.1 mg/cm 3 ) at age 80 years. We show that LDCT-based opportunistic screening could identify large numbers of patients with low lumbar vBMD, and that future cohort studies are now required to evaluate the clinical utility of such screening in terms of fracture prevention and supporting national health economic analyses. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).., (© 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).)

To suppress the rapid spread of coronavirus disease 2019 (COVID-19) in Hubei province, a medical rescue team consisting of 860 members was sent to E'zhou, one of the hard-hit cities in east Hubei. A total of 414 of the team members, whose core members were from Guizhou Medical University and its Affiliated Hospital, took over the full operation of Leishan hospital of E'zhou, a makeshift hospital built for treating COVID-19 patients. Under the instructions by the E'zhou Medical Team Front Command, the staff made quick responses to the surging number of patients with COVID-19 and rapidly formulated treatment plans based on the local conditions. The medical team efficiently carried out the operations and successfully completed the rescue mission. Herein the authors, as members of Guizhou Medical Team supporting COVID-19 containment in E'zhou, analyze and summarize the experiences of Guizhou Medical Team with the organization, implementation and logistic support of medical rescue operations, which may provide reference for future rescue missions in a similar scenario.